Photographs and letters from WWII are not considered “rare” by many collectors in today’s market. I have roughly 1,000 WWI real photo postcards in my current collection, with and additional four albums of 200 or so photos each. Small-run broadsides and posters are much more ephemeral and should be considered scarce. Broadsides were meant to be posted for a few days, taken down and discarded. In this instance, a doughboy in 42nd Rainbow Division took the time to save one of the broadside posters from a wall somewhere in France. The event apparently was some sort of sports exhibition; not an uncommon event in the post-armistice Europe.
Of special attention to WWI buffs out there – check out the presiding chaplain! None other than Father Duffy of the Fighting 69th! A famous WWI movie centers around Duffy and his heroics during WWI. Check it out here.